Develop Reference

Need to modfy the default tab order of child elements

I have custom control like below. When press tab key focus will move in the order elements arrangement.
Query:
When stackpanel receive tab focus I need to change default tab order toggle button present in stackpanel
Default Tab Order:
DockPanel--Border---StackPanel-->Button1-->button2-->button3
Expected Order
DockPanel--Border---StackPanel-->Button3-->button2-->button1
I need update TabOrder based on its parent. Please suggestion solution modify the tab order based on parent
Note: I need UI as like below arrangements, only i need to modify the tab order for buttons
<DockPanel VerticalAlignment="Center" HorizontalAlignment="Center">
<Border x:Name="MainBorder">
<StackPanel>
<ToggleButton>Button 1</ToggleButton>
<ToggleButton>Button 3</ToggleButton>
<ToggleButton>Button 3</ToggleButton>
</StackPanel>
</Border>
</DockPanel>

As mentioned in comments do set the TabIndex property. To step within control do use KeyboardNavigation.TabNavigation attached property.
<DockPanel VerticalAlignment="Center" HorizontalAlignment="Center">
<Border x:Name="MainBorder">
<StackPanel KeyboardNavigation.TabNavigation="Local">
<ToggleButton KeyboardNavigation.TabIndex="3">Button 1</ToggleButton>
<ToggleButton KeyboardNavigation.TabIndex="2">Button 2</ToggleButton>
<ToggleButton KeyboardNavigation.TabIndex="1">Button 3</ToggleButton>
</StackPanel>
</Border>
</DockPanel>
If you want to modify the tab order at run time I would advice you to create a behavior for it. See Use of Behavior in WPF MVVM? To access attached property from code see Get and set WPF custom attached property from code behind

How do I use a textblock for navigation?

I am new to windows dev't and C#, how do make those texts i posted in the code navigate to another xaml page?
Thanks
<StackPanel>
<TextBlock Text="contact us"
TextWrapping="Wrap"
Style="{StaticResource PhoneTextExtraLargeStyle}"
FontSize="{StaticResource PhoneFontSizeExtraLarge}"/>
<TextBlock Text="help"
TextWrapping="Wrap"
Style="{StaticResource PhoneTextExtraLargeStyle}"
FontSize="{StaticResource PhoneFontSizeExtraLarge}"/>
</StackPanel>

There are several ways to do this. Based on what you've described, one way would be to link an event to a Window.Show() method, to show the window. See the links I've provided here for some examples and thoughts, but basically you could insert this into a TextBlock to cause a method to happen when you do a mouse-click on it:
<TextBlock Text="contact us"
TextWrapping="Wrap"
Style="{StaticResource PhoneTextExtraLargeStyle}"
FontSize="{StaticResource PhoneFontSizeExtraLarge}"
MouseUp="MethodToCallNameHere"/>
When you write this in XAML, highlight "MethodToCallNameHere" and press F12, and it will automatically insert a method for you in that Window's code-behind. You can then put in your new window's class there with .Show().
For example, if you wanted to show a new window that is an AboutWindow class (i.e., when you created another XAML window, you named it "AboutWindow"), you could highlight "MethodToCallNameHere" and press F12.
Then, in the created method in the code-behind, you could make it look something like this, to open "AboutWindow" window when the TextBlock is clicked:
private void MethodToCallNameHere(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
// instantiate the new Window's class
AboutWindow aboutWindow = new AboutWindow();
// call the .Show() method to show the new window
aboutWindow.Show();
}
I'd recommend looking through MS's online (and free) documentation on WPF applications here. It's been very helpful to me as I've been learning.

c# WPF how to produce a flashy warning

I'm learning WPF, so bear with me.
I would like to have my WPF application flash in the user's face if a certain event is fired.
What is the best way to "notify" the user? I really want the user to react!
Cheers, Patrick
Environment: Windows7/64bit/.Net4

If you want the user to react you can force them to by simply opening a modal dialogue. The most lightweight of which being the MessageBox. You can also create normal modal windows using their ShowDialog method, you can make those windows as "fancy" as you want by getting rid of their normal appearance. This is achieved by setting the WindowStyle to None and AllowsTransparency to true, this will remove all the frame elements, so the window is now pure content.
Popups are handy for non-modal notifications and they already are content-only, but setting their AllowsTransparency to true may also be desired if you want rounded corners for example.

Best is entirely subjective and depends on many context variables but here is how I do it MVVM style.
In your main view model, define a property
pubic ObservableCollection<AlertViewModel"> Alerts { get; private set; }
in my case the AlertViewModel has only a "Message" property and a "Dismiss" RelayCommand.
In the XAML of your main view add
<Grid>
<all of my other other view controls>
<ItemsControl x:Name="AlertsControl" Opacity="50" ItemsSource="{Binding Alerts}"/>
</Grid>
Make sure it is the last item in the main container of your main view. This ensures it has the highest z order and will appear on top of all other controls.
Here is the data template for this view model
<DataTemplate DataType="{x:Type vm:AlertViewModel}">
<Border CornerRadius="10" Margin="3" Background="Red">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="75"></ColumnDefinition>
<ColumnDefinition></ColumnDefinition>
</Grid.ColumnDefinitions>
<Button Margin="10" Grid.Column="0"
Command="{Binding ElementName=theWindow, Path=DataContext.DismissAlarmCommand}"
CommandParameter="{Binding}">Dismiss</Button>
<TextBlock Foreground="White" FontWeight="ExtraBold" Grid.Column="1"
Text="{Binding Message}" FontSize="20"
VerticalAlignment="Center" HorizontalAlignment="Left"></TextBlock>
</Grid>
</Border>
</DataTemplate>
Now,
Alerts.Add( new AlertViewModel() { Message = "Danger Will Robinson! Danger!" } );
Will pop a Bright red alert box onto the top of your main form. It does not go away until the user presses "Dismiss"
If you want it to flash or fade in and out or bounce up and down you can add animation in the data template.
You can use a Converter or data to Enable/Disable the rest of the controls in the app byt binding to AlertsControl.HasItems
Good luck.

Silverlight: Layout changes when I call NavigationService.Navigate

This is a really weird bug. I have no idea why it could be happening. I know that posting it here is a bit of a long-shot, but I'm out of other ideas.
I have two ListBoxs that act as menus.
<ListBox Margin="56,8,15,0" FontSize="64"
ItemsSource="{Binding FavoriteSections}"
SelectionChanged="MenuList_SelectionChanged">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<toolkit:ContextMenuService.ContextMenu>
<toolkit:ContextMenu>
<toolkit:MenuItem Header="Remove" Click="FavoritesContextMenuItem_Click" />
</toolkit:ContextMenu>
</toolkit:ContextMenuService.ContextMenu>
<TextBlock Text="{Binding DisplayName}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<ListBox x:Name="sectionList" Margin="56,8,15,0" FontSize="64"
SelectionChanged="MenuList_SelectionChanged"
ItemsSource="{Binding SectionViewModels}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<toolkit:ContextMenuService.ContextMenu>
<toolkit:ContextMenu>
<toolkit:MenuItem Header="Add to favorites" Click="SectionContextMenuItem_Click" />
</toolkit:ContextMenu>
</toolkit:ContextMenuService.ContextMenu>
<TextBlock Text="{Binding DisplayName}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The bug exists across both of them.
When the selection changes on either menu, this method is called:
void MenuList_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (e.AddedItems.Count == 0)
{
return;
}
Uri page = null;
object selected = e.AddedItems[0];
if (selected is NavigableItem)
{
NavigableItem selectedItem = (NavigableItem)selected;
page = selectedItem.Page;
}
else if (selected is SectionViewModel)
{
SectionViewModel selectedVM = (SectionViewModel)selected;
page = selectedVM.Section.Page;
}
Debug.Assert(page != null, "What is the type of `selected`?");
// if I comment out this line, the problem goes away:
NavigationService.Navigate(page);
ListBox selectedBox = (ListBox)sender;
selectedBox.SelectedIndex = -1;
}
If I comment out the NavigationService.Navigate() line, the problem goes away. If I replace the line with a different URI, the problem remains.
About 70% of the time, when I click on a menu item, the content jumps all over the page. (The remaining 30%, no bug occurs.) It happens too quickly to see what's really going on, but different UI elements overlap each other.
This only occurs the first time I click on something in those menus during the app's lifetime. If I hit "back" then select a menu item again, the problem will not occur.
What could be happening here? I really have no idea. The code-behind doesn't have a OnNavigatedFrom method, so I don't think it's a problem there.
I'm using Silverlight for Windows Phone 7
Update: Mysteriously, I can't seem to reproduce this in the debugger - only after deploying the app and running it in the emulator unattached. ???
Update 2: The bug appears when NavigationService.Navigate() is called from the Click event handler of a button, as well:
<Button Content="Foo" Click="Button_Click" Grid.Row="0"/>
private void Button_Click(object sender, RoutedEventArgs e)
{
NavigationService.Navigate(new Uri("/Views/sections.xaml?section=43", UriKind.Relative));
}
Looks like the bug has to do with the navigation, not the UI element used to trigger the call.
Update 3: More weirdness. Still not able to reproduce the app while the debugger is attached. If I make the loading progress bar always collapsed, the bug disappears:
<ProgressBar x:Name="LoadingProgressBar"
IsIndeterminate="True"
Visibility="Collapsed"
Style="{StaticResource PerformanceProgressBar}"
VerticalAlignment="Top"/>
Alternatively, commenting out this line in code-behind makes the bug disappear:
LoadingProgressBar.Visibility = Visibility.Collapsed;
I really don't understand what's going on here. That line of code is not executed when the page is navigated from.
Here is the full XAML of the control that's getting messed up:
<ProgressBar x:Name="LoadingProgressBar"
IsIndeterminate="True"
Visibility="Collapsed"
Style="{StaticResource PerformanceProgressBar}"
VerticalAlignment="Top"/>
<TextBlock x:Name="DownloadFailed"
Visibility="Collapsed"
Style="{StaticResource disabledText}"
Margin="56,8,8,-8" >
FooBar.com could not be reached. Do you have a network connection?
</TextBlock>
<ListBox x:Name="sectionList" Margin="56,8,15,0" FontSize="64"
SelectionChanged="MenuList_SelectionChanged"
ItemsSource="{Binding SectionViewModels}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<toolkit:ContextMenuService.ContextMenu>
<toolkit:ContextMenu>
<toolkit:MenuItem Header="Add to favorites" Click="SectionContextMenuItem_Click" />
</toolkit:ContextMenu>
</toolkit:ContextMenuService.ContextMenu>
<TextBlock Text="{Binding DisplayName}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</controls:PivotItem>

The problem lies in your usage of the Indeterminate ProgressBar. All its animations are done on the UI thread, and not the Compositor thread, as is the usual practise. Since you are already using the Windows Phone Toolkit, you can easily replace your ProgressBar with the PerformanceProgressBar offered by the toolkit. This should solve your problems.

Before I begin, let me say that I don't have a lot of experience with Windows Phone, so my answers are based on more generic WPF knowledge, so forgive me if I'm overlooking specifics of the platform, or am referencing features not available.
Some diagnostic questions (sorry this isn't a direct answer):
Firstly, it does seem like Navigate is calling a lot of layoutUpdates. I haven't yet seen what type of container is containing the pages you're updating, but it is worth asking, is that also being disrupted or only the menus?
Secondly, could you try specifying your itemPanel explicitly? You're expecting them to be virtualizingStackPanels, but you may find that some parent object in your visual hierarchy is creating a different inheritance scenario.
You have these in a grid, which is meant to size to its content, or take the default size (100x100 in normal WPF) or take sizing from its parent, which without knowing how you've specified the grid, or the grid's parent, it's difficult to know its behaviour. Furthermore, Grids automatically z-order their children according to the order in which they were added. Can you determine whether it is just the layout of the lisboxes that is being disturbed, or whether it is the entire grid? Or, is it larger than that?
If you attach to the layoutUpdated() event of the listboxes, grid, or grid's parent, you should be able to look at the stacktraces that lead you there - it sounds to me that you'll find that layoutUpdated() is firing more than you'd like it to. Further, you'll be able to output the heights and widths (ActualHeight etcetera of course) during those steps so that you can see when exactly those changes happen.
I hope that some of these diagnostic steps might help you reach an answer.

Disable Drag-drop from TextBox

I have a WPF textBox that is declared as ReadOnly
<TextBox IsReadOnly="True" IsTabStop="False" Width="200" />
So, User can not write anything into the TextBox or delete the content but it still allows user to drag the text from this textbox and drop it in any other textbox that caused the text removed from the first textbox(the read-only one) and thats unexpected. Is it a bug?
how can I get rid of this?

I tried the following code :
<StackPanel>
<TextBox IsReadOnly="True">Hello</TextBox>
<TextBox></TextBox>
</StackPanel>
When I drag-and-drop the text (after selection) from the first TexbtBox to the second one, the text is copied, but not removed from the first TextBox. I tried it under .NET 3.5 and .NET 4.0 targets.
If you want to get rid of your bug without trying to understand it (since it shouldn't happen), you can just put an empty control (Canvas will be ok) on top of your TextBox, with its Background property set to transparent.
<Grid>
<TextBox IsReadOnly="True" IsTabStop="False" Width="200" />
<Canvas Background="Transparent"/>
</Grid>
But the text won't be selectable anymore...